Interventional treatment of giant tracheal lymphoma under rigid bronchoscopy: A case report and literature review

Introduction: Lymphoma can appear in all parts of the body and present with different symptoms. However, bronchial lymphoma is rare and can be misdiagnosed as airway malignancy or lung disease. Patient: An older adult woman with tracheal lymphoma experienced severe breathing difficulties, and chest computed tomography indicated severe narrowing of the airway. She did not respond to repeated antibiotic treatment, and she was eventually diagnosed with lymphoma based on pathology after surgical removal of the tumor. Diagnosis: The patient received a diagnosis of thoracic tracheal stenosis due to intratracheal inflammatory granulomatous lesions or a tumor. Interventions: Treatment involved the use of a high-frequency electrotome, freezing, and argon plasma coagulation. Outcomes: The patient reported improvements in dyspnea, cough, and other symptoms after the operation. The pathological results confirmed follicular lymphoma. Reexamination by fiberbronchoscopy indicated that the degree of stenosis in the middle and upper tracheal segments was significantly reduced following interventional therapy. Conclusion: Endoscopic interventional therapy can be an effective treatment for tracheal lymphoma.


Introduction
Lymphomas commonly lead to widespread lymph node enlargement, bone marrow infiltration, and an enlarged spleen.Primary lesions are not typically found in the trachea and can easily be misdiagnosed as a bronchogenic carcinoma or a benign tracheobronchial tumor. [1]In this case report, we present a 77-year-old woman with follicular lymphoma (FL) involving the trachea, who initially presented with a cough and dyspnea.][5][6][7][8] 2. Case report

Patient information
A 77-year-old Chinese woman had a prolonged history of biofuel exposure.On March 14, 2018, she was diagnosed with chronic obstructive pulmonary disease and stenosis in the upper segment of the trachea, which was observed on chest computed tomography (CT).Since the patient did not experience significant dyspnea or discomfort, no specific treatment was provided at that time.However, she later developed a persistent cough and increased shortness of breath, particularly during physical activities.By June 20, 2018, the patient experienced significant dyspnea (mainly during the inspiratory phase) and was immediately admitted to hospital.Her vital signs were within the normal range, but her oxygen saturation levels were slightly low (SPO 2 , 94% [without oxygen inhalation]).This article has obtained the oral informed consent of the patient family to publish the patient anonymous information in the article.

Clinical findings
Upon examination, there were no signs of the 3-concave deformity during breathing, mouth ulcers, enlarged superficial lymph nodes, weakened tactile fremitus in both lungs, hyperresonance upon percussion in both lungs, coarse breath sounds in both lungs, or scattered wheezing, with only slight moist rales in both lower lungs.Cardiac and abdominal examinations revealed no apparent abnormalities.Blood gas analysis showed a low oxygen partial pressure (pH, 7.440; PaCO 2 ; 34.3 mm Hg; PO 2 , 69.7 mm Hg; BE, 0.3 mmol/L; HCO 3 , 23.5 mmol/L).CT revealed a soft-tissue-like protrusion within the thoracic segment of the trachea, causing narrowing of the airway.This finding was suggestive of an inflammatory granulomatous lesion (Fig. 1).All other laboratory tests yielded normal results.The patient had been previously diagnosed with hypertension, hypertensive heart disease, cerebral infarction, and Alzheimer disease.She reported no history of smoking or drinking.

Therapeutic intervention
The patient was admitted to the hospital and treated with antibiotics, bronchodilators, and anti-inflammatory agents.However, conventional treatment was ineffective.Therefore, we resected the airway mass using bronchoscopy.The newly formed organisms protruding from the lumen were first excised with high-frequency electrocautery.The tissue was then frozen and cut.Hemostasis was achieved with an argon knife.The organism was completely resected, and the degree of tracheal stenosis significantly improved.

Diagnostic assessment
Immunohistochemical staining showed positive expression of CD20, Bcl-2, and Ki67, and negative expression of CD3, CD5, and cyclin D1 (Fig. 2), consistent with FL.The frozen tissue submitted for examination was proliferative lymphoid tissue in a state of nodular hyperplasia.The cells were consistent and most of the normal structures were absent.Neoplastic lymphoma lesions could not be ruled out.A pathological diagnosis was sent for examination (main bronchial neoplasm), which was identified as grade I FL.

Follow-up and outcomes
Postoperatively, the patient felt that the symptoms of dyspnea were significantly reduced.Her vital signs were good.Repeated fiber optic bronchoscopy (Fig. 3) indicated that after interventional treatment of the neoplasms in the upper and middle trachea, the degree of stenosis was significantly reduced, and the surface was covered with yellow-white necrotic substances.The timeline of diagnoses and interventions are shown in Table 1.

Discussion
We reviewed the medical records of 12 patients with tracheal lymphomas who were treated with bronchoscopic interventions (Table 2).To our knowledge, this is the largest series of patients with tracheobronchial lymphoma treated with bronchoscopy.The patients' ages ranged from 15 to 77 years (average: 47 years).The most common clinical symptoms were dyspnea (10/12, 83.33%) and cough (4/12, 33.33%).The most common histological subtypes were mucosa-associated lymphoid tissue lymphoma (3/12, 25%) and anaplastic large cell lymphoma (3/12, 25%), which is consistent with other reports.The most commonly used interventional therapy was stent placement (7/12, 58.33%).Among them, 3 patients also received chemotherapy after surgery.There were no treatment complications except for 1 patient who developed pulmonary thromboembolism on day 7 after surgery and 1 patient who had stent dislocation.Most patients had a good prognosis after interventional therapy; except for 1 patient who died in the 7th month after diagnosis due to insensitivity to subsequent chemotherapy drugs.The remaining patients showed no signs of recurrence during the follow-up period, and their respiratory symptoms were significantly relieved.
Primary tracheal lymphomas are rare.The symptoms are not specific, and if the treatment is not effective or the symptoms worsen, CT or bronchoscopy is performed to identify the lymphoma lesions.A histopathological biopsy is the gold standard for diagnosis.As tracheal lymphoma is rare, there are no diagnostic or treatment guidelines.The treatment of most patients is based on the literature or personal experience.[11] Endoscopic interventional technology has advanced rapidly in recent years.Bronchoscopic interventional therapy is a minimally invasive procedure that can be used to quickly and effectively remove endotracheal lesions.It has several advantages, including low operation costs and good patient prognosis.The combined application of multiple interventional therapy technologies can overcome the shortcomings of each individual technique.Therefore, an increasing number of researchers have used combined interventional techniques to treat benign and malignant tracheal stenoses.This patient was treated with high-frequency electrosurgery combined with cryotherapy and argon plasma coagulation.The high-frequency electric knife degenerates and coagulates diseased tissue.Ice crystals produced by cryoprobes when in contact with tissues can damage organelles.Argon plasma coagulation can continuously transmit the coagulation current output from the electrode to the wound surface, resulting in a hemostatic effect.The advantages and disadvantages of the 3 therapies complement each other, effectively relieving patients' respiratory symptoms, and providing a high level of safety.Some studies have evaluated the safety and efficacy of bronchoscopic interventional therapy for benign and malignant airway tumors, and all have achieved good results. [12,13]n conclusion, tracheal lymphoma is a relatively rare cancer.Its pathogenesis is unknown, and its clinical manifestations are often nonspecific; therefore, it is easily missed or misdiagnosed.Clinicians should be vigilant of patients with recurrent respiratory symptoms and a poor response to conventional treatment.Although there is no guided treatment plan, various treatment modalities have achieved satisfactory results.Compared to conventional radiotherapy and chemotherapy, bronchoscopic interventional therapy is relatively less invasive, has fewer complications, and is an effective treatment method for tracheal lymphoma.

Figure 1 .
Figure 1.Computed tomography (CT) scan of the chest indicating soft-tissue lumen eminence and tracheal stenosis in the thoracic segment of the trachea.